Sql 引用匿名块中的游标
如果返回多个值,如何引用游标的特定值Sql 引用匿名块中的游标,sql,oracle,cursor,Sql,Oracle,Cursor,如果返回多个值,如何引用游标的特定值 DECLARE X INTEGER; CURSOR c1 IS SELECT col1, col2, col3.....; BEGIN OPEN c1; LOOP EXIT WHEN c1%NOTFOUND; FETCH (col2 from c1) INTO X; END LOOP; END; 你为什么要这么做?假设,如果要在游标声明中选择三列,则代码中需要所有三列,因此需要将所有三列提取到三个单独的局部变量中,即 D
DECLARE
X INTEGER;
CURSOR c1 IS SELECT col1, col2, col3.....;
BEGIN
OPEN c1;
LOOP
EXIT WHEN c1%NOTFOUND;
FETCH (col2 from c1) INTO X;
END LOOP;
END;
你为什么要这么做?假设,如果要在游标声明中选择三列,则代码中需要所有三列,因此需要将所有三列提取到三个单独的局部变量中,即
DECLARE
x integer;
y integer;
z integer;
CURSOR c1
IS SELECT column1, column2, column3
FROM some_table;
BEGIN
OPEN c1;
LOOP
FETCH c1
INTO x, y, z;
EXIT WHEN c1%NOTFOUND;
END LOOP;
CLOSE c1;
END;
或者,您可以基于游标声明声明一个记录类型,并获取该记录类型
DECLARE
CURSOR c1
IS SELECT column1, column2, column3
FROM some_table;
c1_rec c1%ROWTYPE;
BEGIN
OPEN c1;
LOOP
FETCH c1
INTO c1_rec;
dbms_output.put_line( c1_rec.column2 );
EXIT WHEN c1%NOTFOUND;
END LOOP;
CLOSE c1;
END;
您还可以完全摆脱显式循环,这通常是首选方法,因为您不必担心光标泄漏,而且(在现代版本中)Oracle可以自动为您执行批量收集
DECLARE
CURSOR c1
IS SELECT column1, column2, column3
FROM some_table;
BEGIN
FOR c1_rec IN c1
LOOP
dbms_output.put_line( c1_rec.column2 );
END LOOP;
END;